<audio src="assets/music/bgm.mp3" autoplay></audio>
<div>
  <a [routerLink]="['./ps']" routerLinkActive="active"> PS</a><br/>
  <a [routerLink]="['./ai']" routerLinkActive="active"> AI</a>
</div>
<a [routerLink] = "['./web']">web</a>
<router-outlet></router-outlet>
